The present invention relates to knitted tulles and methods of knitting tulles.
Tulle is a type of fine netting which has applications in embroidery, lingerie, bridal wear and haute couture as well as in technical areas where the durability and flexibility of netting are of particular importance. Such technical applications include military (e.g. radar reflective netting and parachute netting) and medical applications and as light diffusion fabrics in film and theatre applications.
Bobbinet tulle is a particular type of tulle which was first produced in the early 19th Century following the invention of the bobbinet machine in 1806 by John Heathcoat. The structure of bobbinet tulle provides advantageous properties of uniformity, strength and flexibility. One particularly advantageous property of bobbinet tulle in relation to embroidery is that it is flexible at the scale of the holes in the net structure which reduces the likelihood of yarn breakage when an embroidery needle (especially in machine embroidery) passes through the hole.
Unfortunately, the production of bobbinet tulle, which still uses the mechanisms devised by John Heathcoat, is slow. Bobbinet tulle is thus expensive and so is not, in practice, used in applications where its properties would otherwise make it suitable.
There have been attempts to devise faster production methods for nets or openwork fabrics using knitting machines, in particular, warp knitting machines. GB-A-1,275,448 relates to a method of producing patterned net fabrics on a Raschel warp knitting machine. GB-A-2,325,674 relates to an openwork knitted fabric that has a high capacity for absorption of size and so can be made harder and stiffer than previous fabrics.
There have also been attempts to produce knitted tulles or tulle-like materials. GB-A-1,230,232 relates to tulle having hexagonal openings produced on a Raschel knitting machine.
Unfortunately, the tulle described in GB-A-1,230,232 has a pattern which is very sensitive to differences in tension in the inlay threads. Unless the tension in each inlay thread is the same, the tulle is extremely distorted. It is, in practise, very difficult to control the tension of the inlay threads to the required degree because even a relatively narrow warp knitting machine may have over 5,000 separate inlay threads.